[Coco] CocoSDC .vhd images

[Jeff Teunissen]

The CoCo SDC does work with double-sided disk images, just not all of
them. If an image has more than 2880 sectors (720K), the SDC doesn't
recognize it as a floppy. That means funky formats like 83-track
double-sided 20 sectors per track (which I have seen) don't work, but
any disk image that's exactly 720K should.

Any DSK image larger than 180K is _assumed_ to be double-sided.

On Mon, Apr 26, 2021 at 7:57 AM <coco at jechar.ca> wrote:
>
>
> Back in the Day ( Early 90's ) Double sided floppy disks were common
> enough
> SDC should really see if they can extend there support to double sided,
> if
> not auto-detect at least by allowing the user to specify the type. A lot
> of
> my floppy's from that time were DSDD 720K and SDC seems to be
> inconsistent about reading them especially in SDC Explorer.
>
> On 2021-04-24 13:56, David Ladd wrote:
> > On Sat, Apr 24, 2021 at 9:58 AM Robert Gault <robert.gault at att.net>
> > wrote:
> >
> >> I am probably missing something obvious but I am having problems
> >> creating
> >> .vhd images that will boot into NitrOS9 on the CoCoSDC.
> >>
> >
> > For cobbler, os9gen, and other boot track management utilities to
> > correctly
> > modify the boot(kernel) track you need to make sure that the sides is 1
> > and
> > sectors per track are 18 with new HDD images.  Reason for this is the
> > firmware of the CoCoSDC treats HDD sized images as a single sided
> > device at
> > 18 sectors per track when in floppy emulation mode.
> >
> >
> >
> >
> >
> >> I created a large .vhd image and formatted it on th SDV. I mounted a
> >> disk
> >> that will boot in SDC drive 0 and the new disk in SDC1. I wrote a
> >> Basic
> >> program to copy track 34 to the new disk. Booted NitrOS9 and marked
> >> the
> >> sectors for track34 as used with ded. I then ran an edited mb.floppy
> >> to
> >> create an OS9Boot file, the CMDS directory, and startup.The new disk
> >> with
> >> the SDX explorer does not show that it can be booted. With the DOS
> >> command
> >> it got part way through the boot but did not have the needed RBF
> >> drivers.So, I used the good .vhd to boot, deleted OS9Boot from the new
> >> .vhd
> >> and copied over OS9Boot from the good disk. Using ded I adjusted
> >> sector 0
> >> to point to the boot file and set the length for the new disk. The new
> >> disk
> >> still will not boot and does not show the needed RBF files even though
> >> they
> >> are in OS9Boot.
> >>
> >
> > If you are using the CoCoSDC boot track that has the BOOT module that
> > is
> > designed for the HDD LBA mode of the CoCoSDC then should load the
> > OS9Boot
> > file as normal.
> >
> >
> >
> >> Something is causing SDCDOS to use an incorrect OS9Boot file that is
> >> not
> >> showing in the main directory. Sector 0 is pointing to the OS9Boot
> >> file
> >> that shows in the directory. There is no info I can find in the docs I
> >> have
> >> on the CocoSDC and SDC explorer that explains what is happening.
> >>
> >> Sent from AT&T Yahoo Mail on Android
> >>
> >> --
> >> Coco mailing list
> >> Coco at maltedmedia.com
> >> https://pairlist5.pair.net/mailman/listinfo/coco
> >>
> >
> >
> > Sincerely,
> > David Ladd
> > ***END OF LINE***
> > +-----------------------------------------------------------------------+
> > | David Ladd a.k.a. PacoOtaktay a.k.a. Drencor
> > |
> > | YouTube: http://www.youtube.com/user/PacoOtaktay
> > |
> > | YouTube Gaming Live: https://gaming.youtube.com/user/PacoOtaktay/live
> > |
> > | Websites are:
> > |
> > |   http://daves-hobbies.com
> > |
> > |   http://dwladd.com
> > |
> > |   http://www.theterrorzone.com
> > |
> > |
> > |
> > | Do you have your CoCo 3 yet?
> > |
> > +-----------------------------------------------------------------------+
>
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